Coatings on strips



Mamh 1955 K. A. NILSEN ETAL 2,704,530

MACHINE FOR THE APPLICATION OF SURFACE COATINGS ON STRIPS Filed June 12,1952 United States Patent MACHINE FOR THE APPLICATION OF SURFACECOATINGS ON STRIPS Knut Anders Nilsen and Johan Wleiigel, Oslo, Norway,assignors to A/S Nordisk Aluminiumindustri, Oslo, Norway ApplicationJune 12, 1952, Serial No. 293,187

Claims priority, application Sweden June 19, 1951 2 Claims. (Cl.118-224) In the surface treatment of strips of metal or other material,the treatment may be performed in steps, each step forming a separateoperation. It is convenient to make the strip or strips pass the varioustreatment steps continuously and to adjust theconditions of eachindividual step in such a manner that the material which continuouslyleaves the apparatus has a surface coating of uniform and satisfactorycharacteristics.

A very important link in such a continuous treatment process is formedby the machine applying the surface coating. Any fault or imperfectionin the functioning of this machine, for instance causing the machine tostop, might involve an incorrect step in the other treatment steps andthereby damage the characteristics of the strip material and of thecoating; any stoppage also meaning a production loss.

Previous constructions of machines adapted for the application ofsurface coatings on continuously running strips have been of limitedutility for this special purpose. Thus, during the application of alacquer coating, it has been necessary, in order to avoid faulty spotsin the same, to stop the machine and thereby the continuous process, inorder to replace the application rollers by the often occurring faultsin the sensitive rubber or gelatinous surfaces of the same. Further, ithas also, for instance, been impossible to apply one lacquer coatingontop of another in one machine.

The present invention relates to a machine adapted to effect theapplication of a surface coating to continuously running strips by meansof application rollers, whereby stoppages in the application of thecoating are avoided even by the replacement of an application roller.The application is only interrupted for a very short length of thestrip, viz. on both sides of a strip joint.

According to the invention, this is achieved by providing the machinewith two application systems which may operate completely independentlybut are driven in synchronism, and which may be used separately oroperate in conjunction for the consecutive application of similar orvaried (complex) coatings. Thus, the machine may for instance be adaptedfor the immediately consecutive applications of two similar lacquerfilms, of different thickness, in such a manner that the film lastapplied covers possible deficiences or pin holes etc. in the underlyingfilm. As the application systems are so made that they may operatecompletely independent, it is for instance also possible to apply twoinequal lacquers which in combination give more favourable results thanis obtainable with two lacquer qualities used separately.

A machine according to the invention is made in such a manner that onecomplete application system or parts of the same may be renderedeffective without stopping the machine or the application process. Theapplication of the coating is in the meantime effected by means of theremaining application system only. Further, each individual roller ofthe two application systems is so mounted that the distance between theindividual rollers may be varied without varying the distance betweenthe same rollers and the remaining rollers of thelsystem, which factalso involves the great advantage that the adjustment of the thicknessof the coating may be effected much more easily than in any other knownmachines.

Thus, any roller in the application system may be re e the direction ofthe arrow through the machine.

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placed independently of the remaining rollers or the driving means ofthe same.

Finally, a machine according to the invention is characterised in thatthe two rollers between which the strip is passing, the application andcounterpressure rollers, may temporarily be set apart for instance whenthe strip joints are passing the rollers. The construction of themachine enables the raising and lowering, respectively of the rollers,separately or together, perpendicularly to the strips, independently ofeach other and without influencing the adjustment of the remainingrollers of the application systems. In the embodiment of the machine nowto be described with reference to the accompanying drawings, thecounterpressure rollers are, for practical reasons, so mounted thattheir position relative to the corresponding application rollers iscontrolled by at least one eccentric which by external influence may becaused to make one revolution and thereby temporarily move eachindividual counterpressure roller relatively to the correspondingapplication roller, the distance between the individual roller pairsbeing unchanged after one revolution of the eccentric.

It has been found especially convenient to enable the rollers to beautomatically moveable relatively to each other when an inequality is topass. According to the present invention, this is obtained so that theeccentric movements are automatically controlled by a feeler whicheffects the eccentric motions when the inequalities are to pass therollers. In order to make the portion of the strip length which is thenwithout coating as short as possible, the machine is so made that thetwo counterpressure rollers are displaced with a relative time delaycorresponding to the travelling speed of the strip. Thus, the twoeccentric means may be interconnected in any suitable manner in order toachieve the desired result, but it is found convenient to arrange themeans to be driven from separate shafts.

As stated, the eccentric means may also be arranged in conjunction withthe application rollers proper, but in the embodiment shown it has beenfound suitable to move the counterpressure rollers automatically whilethe movement of the application rollers proper, in case the automaticmeans of any reason might fail, may be manually controlled by means ofsuitably arranged raising handles.

The invention is now to be more closely described under reference to theaccompanying schematic drawing, which illustrates one embodiment of themachine. It will be appreciated that the drawing only shows such partsof the machine which are considered essential for the understanding ofthe invention, while other parts which might be required for theoperation of the machine are deleted, partly because the same may bemade and arranged in many different ways and partly in order not to makethe drawing obscure.

Obviously the present invention is also advantageously applicable tomachines adapted to perform a double-sided lacquering of the strips.

In the drawing,

h Figure 1 is a longitudinal schematic view of the mac me.

Figure 2 is a partial sectional view taken along the line A--A of Figure1.

In the drawing, 1 is the strip which is to be coated and which ispresumed to be continuously runningnin e machine is provided with twocoating application systems which in their entirety are designated I andII and which may be completely similar and for the purpose ofsimplicity, the same reference characters are used for systems I and II.

In the embodiment shown, each application system comprises a trough 2containing the coating substance and wherein a rotating roller 3 ispartly immersed. From the said roller 3 the coating substance istransferred to one or more transfer rollers 4 and thence to theapplication roller proper 5, which transfers the coating substance tothe strip 1 when the latter is pressed against the roller 5 by means ofa counterpressure roller 6. The adjustment of the quantity of coatingsubstance transferred from the trough 2 and thereby the thickness of thefilm applied to the strip 1 is effected by adjustment of the variousrollers relatively to each other, viz. according to the invention byindividual adjustment of the various rollers without therebynecessitating any adjustment of the other rollers. The machine accordingto the invention is adapted for the displacement of the various rollersby means of any suitable means, such as screw spindles. For the sake ofconvenience the displacement means referred to are indicated in thedrawing by dot-and-dash lines only, viz. the line 3a corresponding tothe roller 3, the line 4a for the roller 4 and the line 5a for theroller 5.

In addition to the said adjustment means, provisions are, as stated,made for the automatic and temporary removal of the counterpressureroller 6 from the application roller 5 in order to pass possiblethickenings, such as joints appearing between the individual striplengths.

For this purpose, each of the counterpressure rollers 6 is at each endmounted in a vertical sliding bearing 7 which by means of a rod 8 isconnected to an eccentric 9 mounted on a shaft 10 or 11, respectively,so that each of the rollers 6 may perform a reciprocal vertical movementrelatively to the corresponding application roller 5 during onerevolution of the shaft 10 or 11, respectively. The shafts 10 and 11 arenormally not rotating, but are caused to make one revolution with thecorrect relative time interval when a thickening appears in the strip 1being fed through the machine. The means used for this purposecomprises, in the embodiment shown in the drawing, a raising magnet 12which is actuated in any suitable manner, for instance by means of afeeler (not shown), the position of which depends upon the thickness ofthe strip 1. When the raising magnet 12 is actuated a shaft 13 makes apart of a revolution so that the tongues 14 and 15 are moved and releasecorresponding blocking projections 16 and 17 on clutches 18 and 19,respectively. The clutch 19 is then caused to engage a permanentlyrotating idle pinion 20, whereby the shaft 21 carrying the fixed pinion22 is rotated. The pinion 22 is in engagement with idle pinions 23 and24 and by the release of the blocking projection 16 the clutch 18 andthereby the shaft 10 and the eccentric 9 are rotated, whereby thecounterpressure roller 6 of application system I is moved downwardly asdescribed above. The pinion 22, previously referred to is provided witha catch 25 which, when moved through a certain arc hits the release hook26 and carries the same away from the blocking projection 27 therebycausing the clutch 28 to engage the idle pinion 24, so that the shaft 11and the said eccentric 9 are caused to rotate whereby thecounterpressure roller 6 of application system II is moved away from thecorresponding application roller 5 as described above. The releasetongues 14, 15 and 26 are returned to their initial positions beforeeach of the clutches 18, 19 and 28 has made one revolution, with the endthat the motions are interrupted when each of the shafts 10, 11 and 21has made exactly one revolution. The arc to be passed by the catch 25before the same acts upon the blocking projection 26, is so adjustedrelatively to the travelling speed of the strip 1 that a joint which hasbeen passed by application system I will just be arriving at applicationsystem II, whereby not only both application rollers are protectedagainst damage, but the length of the strip 1 which does not receive anycoating is made of the shortest length possible.

In addition to the possibility of lowering the counterpressure rollers,provisions may be made for instantaneous raising of the applicationrollers proper along the line 5a by a suitable external influence incase some unequality is observed which might damage the rollers.

The operation of the machine and the various gears for the provision ofthe correct relationship between the speeds of the various rollers, aswell as the arrangement of pumps for the coating substance to thetroughs 2 obviously may be made in any suitable manner, it beingconsidered unnecessary to the understanding of the present invention toenter into details in this connection.

We claim:

1. A machine for the application of a continuous coating upon thesurface of a strip and particularly a continuously moving strip of metaland the like comprising two independently operable coating applyingassemblies arranged in predetermined relation to the strip with theassemblies being arranged in immediate succession with respect to eachother relative to the path of movement of the strip, each applyingassembly including a rotatable roller, a rotatable counter-roller of thepressure type urging the strip against the roller, means to applycoating material to the roller, a journal for the counterroller, guidemeans supporting the journal for movement toward and away from thestrip, eccentric means, a shaft member on which the eccentric means isrotatably mounted, means interconnecting said eccentric means and thejournal of the counter-roller, drive means to effect a single rotationof the shaft member, and control means to actuate the said drive means.

2. A machine as defined in and claimed by claim 1 further characterizedin that delay means is connected between each eccentric means wherebyafter the operation of one eccentric means, a predetermined time delayoccurs before the operation of the other eccentric means.

References Cited in the file of this patent UNITED STATES PATENTS1,375,126 Willwerschield Apr. 19, 1921 1,663,232 Ambler Mar. 20, 19282,246,126 Davies June 17, 1941 2,573,097 Epstein Oct. 30, 1951 2,614,522Snyder Oct. 21, 1952 2,651,283 Zinn Sept. 8, 1953

